ionice – renice you IO activity for the process.

ionice is utility provided by the package util-linux. Description of util-linux:

Description : The util-linux package contains a large variety of low-level system
: utilities that are necessary for a Linux system to function. Among
: others, Util-linux contains the fdisk configuration tool and the login
: program.

With the help of this utility, you can set the scheduler priority for your IO scheduling upto RealTime, but be careful that can make other process sluggish. Example use: